“In Marvel Studios’ Thor: Ragnarok, Thor is imprisoned on the other side of the universe without his mighty hammer and finds himself in a race against time to get back to Asgard to stop Ragnarok – the destruction of his homeworld and the end of Asgardian civilization – at the hands of an all-powerful new threat, the ruthless Hela. But first he must survive a deadly gladiatorial contest that pits him against his former ally and fellow Avenger – the Incredible Hulk!”

That "other side of the universe" location is almost certainly Planet Hulk setting, Sakaar, which director Taika Waititi has confirmed will play a part in the story previously. Planet Hulk incorporates a storyline where an enslaved Hulk takes part in gladiatorial combat, so it seems at least a portion of the comic series will be kept intact.